The Toddler Module of the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a fifth module that is specifically designed to assess children with limited expressive language who are between the ages of 12 and 30 months. Similar to the other ADOS-2 modules, the Toddler Module consists of standardised activities in which communication, social interactions, and restricted and repetitive behaviours relevant to the diagnosis of autism spectrum disorder (ASD) can be observed.